The smallest unit written to magnetic tape media is the Data Set. If the size of data being written in a transaction is smaller than the size of a Data Set, performance is adversely affected because the space of a full Data Set is still allocated. Moreover, writing fewer codeword quads (CQs) than a full Data Set precludes interleaving because the CQs can't be spaced as far apart as when a full Data Set is written. Consequently, the ability of ECC to correct errors is reduced.